| 摘要 |
<p>PROBLEM TO BE SOLVED: To complete polishing in a short time even if a measurement error due to inclination of a substrate occurs, and to precisely correct the error.SOLUTION: A Z-axial table 13 can be moved vertically by a servomotor 14 and is brought under the full closed control of a control part 17, so that while a precise position measurement is taken, the Z-axial table 13 is moved in a vertical direction of a polishing surface 3a of a polishing tape 3 to be positioned at a stop position. A height measuring instrument 20 is connected to an arithmetic part 17a, and the distance between the polishing surface 3a and a surface of a glass substrate 4 is computed based upon a vertical movement distance of a pair of contact fingers 27a, 27b. The control part 17 controls the Z-axial table 13 and a tape supply mechanism and calibrates a movement quantity of a polishing head 18 according to the computation result so as to accurately polish a projection defect A.</p> |
